1. Field of the Invention
This invention relates generally to packaging articles by depositing them in a receptacle and, more particularly, to automatically packing a succession of layers of articles upon another in an open receptacle.
2. Description of the Related Art
Fruit and vegetables are typically packed in receptacles such as cartons or crates, to be transported to distribution warehouses, grocers, and consumers. In the case of spherical fruit, such as oranges, the packing typically is accomplished by arranging the fruit on two feed chutes that feed the fruit to positions at the end of each chute in rows so as to form arrays of closely-arranged fruit. A carton or other receptacle is positioned between the two chutes, and successive alternate fruit arrays are lifted from each feed chute by an associated lifting head and are placed into the box. Fruit arrays are lifted and placed in the carton until it is filled, at which point the carton is taken away and a new carton is placed into position. A lifting apparatus of this general type is described, for example, in U.S. Pat. No. 3,453,802.
Movable guide panels have been used to center each rectangular carton being filled with fruit and to guide the fruit arrays past the carton's top edge. The guide panels generally comprise short, curved ramps that are moved downwardly over the top edge of the carton before the lifting heads insert the fruit. The guide panels apply equal forces to opposite walls of the carton and thereby center it. The guide panels also reduce the amount of friction experienced by the fruit while being placed in the box, reducing damage to the fruit. After the box is filled, the guide panels are retracted and the carton is moved away. A packing apparatus using such guide panels, for example, is discussed in U.S. Pat. No. 4,386,491.
Although the aforementioned guide panels improve the operation of such a packing apparatus, there may be slight variations in the dimensions and construction of the receptacles that result in non-centering of receptacles and make the guide panels less than optimal. Also, although the guide panels help to properly position the fruit arrays within the receptacle, it is possible for the fruit to come into contact with the sides of the receptacle after the fruit has descended below the level of the guide panels. This contact can damage the fruit and can lead to spoilage. Variations in dimensions and damage from contact are more likely where the receptacles take the form of wooden crates.
Thus, there is a need for a fruit-packing apparatus that centers a receptacle in position for a lifting head and that protects the fruit from contact with the interior walls of the receptacle. There is also a need for such an apparatus that can accommodate receptacles of different sizes and construction. The present invention meets that need.